LG2A

Laboratoire de Glycochimie, des Antimicrobiens
et des Agroressources UMR 7378 CNRS

UMR 7378 CNRS

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Actualités et Publications

Design, Synthesis and Antibacterial Activity Evaluation of 4,5-Diphenyl-1H-Imidazoles Derivatives,

Bamoro, C.; Bamba, F.; Steve-Evanes, K. T. D.; Aurélie, V.; Vincent, C.

Open Journal of Medicinal Chemistry 2021, 11, 17-26.

Due to the continuous emergence and rapid spread of drug-resistant strains of bacteria, there is an urgent need for the development of novel antimicrobials. Along this line, the synthesis and antibacterial activity of 4,5-diphenylimidazol-2-thiol derivatives 2a-g and 6a-e are reported. The structures of the synthesized compounds were confirmed by Nuclear Magnetic Resonance (NMR) and High Resolution Mass Spectrometry (HRMS). All compounds were screened in vitro for their antibacterial activity against Pseudomonas aeruginosa and Escherichia coli (Gram-negative bacteria) and also against Staphyloccocus aureus and Enterococcus faecalis (Gram-positive bacteria). The results showed most of the synthesized compounds have no antibacterial activity. However compound 6d was two-fold potent than ciprofloxacin against Staphylococcus aureus with Minimum Inhibitory Concentration (MIC) of 4 μg/mL and 6c showed moderate biological activity against Staphylococcus aureus (16 μg/mL) and Enterococcus faecalis (16 μg/mL).

Protein–Protein Interface Topology as a Predictor of Secondary Structure and Molecular Function Using Convolutional Deep Learning,

Bouvier, B.

J. Chem. Inf. Model. 2021.

To power the specific recognition and binding of protein partners into functional complexes, a wealth of information about the structure and function of the partners is necessarily encoded into the global shape of protein–protein interfaces and their local topological features. To identify whether this is the case, this study uses convolutional deep learning methods (typically leveraged for 2D image recognition) on 3D voxel representations of protein–protein interfaces colored by burial depth. A novel two-stage network fed with voxelizations of each interface at two distinct resolutions achieves balance between performance and computational cost. From the shape of the interfaces, the network tries to predict the presence of secondary structure motifs at the interface and the molecular function of the corresponding complex. Secondary structure and certain classes of function are found to be very well predicted, validating the hypothesis that interface shape is a conveyor of higher-level information. Interface patterns triggering the recognition of specific classes are also identified and described.

IL versus DES: Impact on chitin pretreatment to afford high quality and highly functionalizable chitosan,

Huet, G.; Hadad, C.; González-Domínguez, J. M.; Courty, M.; Jamali, A.; Cailleu, D.; van Nhien, A. N.

Carbohydr. Polym. 2021, 269, 118332.

Chitin is mainly extracted from crustaceans, but this resource is seasonally dependent and can represent a major drawback to satisfy the traceability criterion for high valuable applications. Insect resources are valuable alternatives due to their lower mineral content. However, the deacetylation of chitin into chitosan is still an expensive process. Therefore, we herein compare the impact of both DES/IL-pretreatments on the efficiency of the chemical deacetylation of chitin carried out over two insect sources (Bombyx eri, BE and Hermetia illucens, HI) and shrimp shells (S). The results showed that chitosans obtained from IL-pretreated chitins from BE larva, present lower acetylation degrees (13–17%) than DES-pretreated samples (18–27%). A selective N-acylation reaction with oleic acid has also been performed on the purest and most deacetylated chitosans leading to high substitution degrees (up to 27%). The overall approach validates the proper chitin source and processing methodology to achieve high quality and highly functionalizable chitosan.

Effects of CoCl2 on the regioselective tosylation of oligosaccharides,

El-Abid, J.; Moreau, V.; Kovensky, J.; Chagnault, V.

J. Mol. Struct. 2021, 130609.

The tosyl functional group is commonly used in carbohydrate chemistry as a nucleofuge. Tosylation of the primary hydroxyls of carbohydrates are generally performed after orthogonal protection/deprotection reactions. However, it can be done regioselectively from unprotected sugars. Several examples have been described in the literature starting from free monosaccharides. Yields are generally good but may vary according to the nature of the sugar. Starting from free oligosaccharides, the regioselectivity and the yields generally drop significantly. The use of catalysts, such as DMAP or NEt3, improves the conversion but to the detriment of the regioselectivity. In our current work, we developed a tosylation reaction of the primary positions of several oligosaccharides with improved regioselectivity, using cobalt II chloride in catalytic amounts. Adaptability of this methodology has been tested on cellobiose, maltose, lactose, sucrose and maltotriose.

Synthesis and interfacial properties of new 6-sulfate sugar-based anionic surfactants,

Abdellahi, B.; Bois, R.; Golonu, S.; Pourceau, G.; Lesur, D.; Chagnault, V.; Drelich, A.; Pezron, I.; Nesterenko, A.; Wadouachi, A.

Tetrahedron Lett. 2021, 153113.

Three families of anionic sugar-based surfactants bearing a sulfate functional group on the primary position of a monosaccharide were synthesized and their physicochemical properties were compared. The first family corresponds to 6-sulfate derivatives of commercially available octa- and dodecyl β-D-gluco- and galactopyranosides. The second and the third families contain an amide linker between the sulfated monosaccharide (galactose, glucose or xylose) and the hydrophobic alkyl chain. Twelve of the as-synthesized anionic glycolipids, including nine novel sulfated compounds, were investigated for their surface activity at the air/liquid interface and for their self-assembling properties. These sugar-based surfactants show surface properties similar to those of commercial anionic surfactants (SDS and SLES) with good ability to reduce surface tension. The obtained results confirm the interest in these new bio-based molecules for potential substitution of anionic surfactants in various formulations.

One-Pot Synthesis of Asymmetrically Difunctionalized Oligomaltosides by Cyclodextrin Ring Opening,

Pélingre, M.; Smadhi, M.; Bil, A.; Bonnet, V.; Kovensky, J.

ChemistryOpen 2021, 10, 493-496.

Abstract The synthesis of pure difunctionalized hexa-, hepta- and octamaltosides was performed by one-pot chemical reaction from perbenzoylated cyclodextrin. Oligomaltosides with azide, propargyl or allyl on reducing end and an unprotected hydroxyl group on non-reducing end were obtained from perbenzoylated α-, β- and γ-cyclodextrin with 12 to 48 % yields.

Synthesis of new sulfated disaccharides for the modulation of TLR4-dependent inflammation,

Naitaleb, R.; Denys, A.; Allain, F.; Ausseil, J.; toumieux, s.; Kovensky, J.

Org. Biomol. Chem. 2021.

Natural sulfated glycans are key players in inflammation through TLR4 activation, and therefore synthetic exogenous sulfated saccharides can be used to downregulate inflammation processes. We have designed and synthesized new sulfated compounds based on small and biocompatible carbohydrates able to cross the BBB. Suitable protected donor and acceptor, obtained from a unique precursor, have been stereoselectively glycosylated to give an orthogonally protected cellobiose disaccharide. Selective deprotection and sulfation allowed to synthesize four differentially sulfated disaccharides, which have been characterized by NMR, HRMS and MS/MS. Together with their partially protected precursors, the new compounds were tested on HEF-TLR4 cells. Our results show the potential of small oligosaccharides to modulate TLR4 activity, confirming the need of sulfation and the key role of the 6-sulfate groups to trigger TLR4 signalization.

Hybrid Electrolytes Based on Optimized Ionic Liquid Quantity Tethered on ZrO2 Nanoparticles for Solid-State Lithium-Ion Conduction,

Bidal, J.; Becuwe, M.; Hadad, C.; Fleutot, B.; Davoisne, C.; Deschamps, M.; Porcheron, B.; Nhien, A. N. V.

ACS Appl. Mater. Interfaces 2021.

This paper describes the simple, highly reproducible, and robust synthesis of a new solid organic/inorganic electrolyte based on the ionic liquid (IL) 1-butyl-3-(carboxyundecyl)imidazolium bis(trifluoromethylsulfonyl)imide tethered to zirconia nanoparticles (15–25 nm) by coordination and named ZrO2@IL. The IL monolayer formation, ensured by two-dimensional solid-state NMR, at the nanoparticles’ surface considerably reduces both the IL’s consumption and the IL amount at the ZrO2 surface compared to the IL-based hybrid electrolytes reported in the literature. After LiTFSI, used as a lithium source, content optimization (26 wt %), the hybrid exhibits unprecedented stable conductivity passing from 0.6 × 10–4 S.cm–1 to 0.15 × 10–4 S.cm–1, respectively, from 85 °C to room temperature (25 °C). Unlike silica which is commonly adopted for this type of hybrid material, zirconia makes it possible to produce more impact-resistant pellets that are easier to compact, thus being favorable for accurate conductivity studies and battery development by electrode/composite/solid electrolyte layer stacking. The ZrO2@IL/LiTFSI solid hybrid electrolyte’s thermal stability (up to 300 °C) and performance make this electrolyte suitable for lithium conduction in all-solid-state batteries.

CHAPTER 4 Carbon Nanostructures and Polysaccharides for Biomedical Materials,

González-Domínguez, J. M.; Álvarez-Sánchez, M. Á.; Hadad, C.; Benito, A. M.; Maser, W. K.

Carbon Nanostructures for Biomedical Applications 2021, 98-152.

Even though many members from the broad family of carbon nanostructures have been known to us for decades, and despite their promising potential in biology and medicine, there is still a long way ahead to reach the goal of using them in real applications. The cause of such a gap still lies in the persistent drawbacks of insolubility, processability difficulties, poor consistency of macroscopic assemblies and surface inertness of carbon nanostructures. However, solely their direct chemical derivatization might not solve the problem right away. New processing elements need to come into play, but this also twists the whole picture, as the toxicity and performance profiles become more complex. We herein analyse the potential of natural polysaccharides (with a particular focus on cellulose) towards hybrid materials and structures for biomedical purposes. The role that these biopolymers acquire when interfacing with carbon nanostructures goes far beyond a mere dispersing effect, but instead creates unprecedented synergies leading to hydrogels, aerogels, films or fibres with high biocompatibility and bioactivity. In this chapter, the history of carbon nanostructures and natural polysaccharides in the field of biomedical applications will be respectively reviewed, to subsequently go into detail of specific hybrids made with the most relevant biopolymers (namely cellulose, chitin, chitosan and alginate) with extraordinary prospects in biomedicine.



Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources
UMR 7378 CNRS
10 rue Baudelocque
80039 Amiens Cedex
tel/fax : 33 (0)3 22 82 75 60
N° SIRET : 19801344300017